Sheshbazzar

Having just reviewed all of the threads that Toto referenced above, I recalled something that I had read long ago, that seems to me to have a certain bearing on this subject, although I've I have never seen it brought up anywhere before.
Perhaps because most never get around to reading or much discussion of the non-canonical books.
empathises mine.

First I would like to direct your attention to the strong desire to protect Jewish nationalism that is an integral element of this narrative, and is being expressed in the phrases used in the 10th, 11th, and 14th verses above;
" being at the point to be put from their law, from their country, and from the holy temple:"
and;
"to be in subjection to the blasphemous nations."
Although the texts we have are from the Greek, a very strong pro-Jewish/Hebrew cultural sentiment is evidenced throughout, and basically consists of a record of the attempts of the Jewish people to preserve their own culture, religion, traditions, (and speech) from being wholly overwhelmed by "the blasphemous nations." or as both text and history indicates, the Greeks and sprawling Hellenic civilization with its attendant "Hellenization" of everything in its domain.

Now on to this "WATCHWORD" matter, it could well have been the genesis of an ongoing expectation of divine "HELP", "SAFETY" and "VICTORY". And of a "watchword" that would ultimately be transitioned into a "NAME" that "SAVES" or promises "VICTORY" and "TRIUMPH" over all of Israel's adversaries.
Such a "watchword" as pronounced in Hebrew, would likely correspond quite closely with some form of the Hebrew name "YAHshua" or "YAH'oshua".

Now none of this is at all intended to imply that any such individual ever need have existed, but serves only as an explanation of how a natural transition from an iconic Jewish/Hebrew "watchword" into an ideal "Name" for the expected Messiah could well have occurred, one that would have been eagerly accepted and employed by those among the nationalistic Hebrew speaking Jews with strong Messianic expectations.

There are many "undercurrents" within the NT texts that suggest the name of the messiah is a watchword, and that that name contained a theophonic element;
"For whosoever shall call upon the name....." (Joel 2:32, Acts 2:21, Romans 10:13) and more.
"Whosoever" is all inclusive, thus a particular "name" being used as a "watchword" would correspond to the ancient "shibboleth" password; Thus, admit or exclude, pass or fail, life or death, "salvation" or destruction.

Minimalist

The powers-that-be will screw you over every time.